Electronic equipment involving semiconductive devices are essential for many modern applications. Technological advances in materials and designs have produced generations of semiconductive devices where each generation has smaller and more complex circuits than the previous generation. In the course of advancement and innovation, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component that can be created using a fabrication process) has decreased. Such advances have increased the complexity of processing and manufacturing semiconductive devices.
Metal-oxide semiconductor (MOS) transistors are fundamental components in modern IC designs. Further, the feature fidelity of MOS transistors, including the geometries of the gate and the source/drain regions, is crucial to device performance as feature sizes continue to decrease. Among the advances of manufacturing MOS transistors, a replacement gate process may be implemented to address the concerns of high temperature processing on metal materials. In the replacement gate process, a dummy gate is initially formed and processing may continue until deposition of an interlayer dielectric (ILD). The dummy gate may then be removed and replaced with a metal gate.